bayer



l 1l... jl. BAYER.,

` som 'BLOWER Foa BOILERS, l APP'Llc'ATloN HLED'NovJs. 19u. l ll'f.. 1 PatentedSept.'30,1919

3 sHmssHEET 14.

l l l ll /lll,//

/NVENTO/Q.

Lo (fno, Bayer- A T TOR/VE Y.

` V.L,. J. BAYER. sooT'BLeWER FOR Homes.

APPLICATION-FILED NOV. I-6. 1917.

Patented Sept. 30, 1919.

3- SHEETS-SHEET 3.

Le@ M210. @d5/ery D STATES terroir..

LEO'JNO. BAYER, or s'r. LOUIS, MIssoUItI, AssIGMon To BAYER STEAM soor BLOWER COMPANY, or sT. LOUIS, MISSOURI, a CORPORATION or MISSOURI.

SOOT-BLOWER FOB, BOILERS.

To all who-m t may concern Be it known that l, Lito JOHN BAYER, a-

citizen vofthe United States, 'residing at St. Luis,vState of Missouri, have invented cer- 5 tain new and useful Improvements in Soot- Blowers for Boilers, of whichthe following isa full,.clear,`and eXact description, reference being had to the accompanying drawings, forming a part hereof.

The present improvement is particularly directed to soot-blowers (sometimes called boiler cleaners)v intended to operate in conjunction with a type of water-tube boilery known as'the Stirling boiler in which tWO i5 or morneJ (usually three) transversely disposed, parallel steamfand-water drums are lconnected with a single mud drum by means of Awater ciroulatingtubes leading from the bottoms of each of the steam-and water drums to the top ofthe-mud drum, the steam space of the center'drum being connected to both the front and rear drums (where three drums are used) by a row of steam circulating tubes, and being connected to the water sp-ace of the front drum by water circulating the furnace of the boiler.

tubes, the number of which tubes'depend on the class of boiler. rlhe center drum` being the highest, the steam outlet is placed on the top of this drum.` ln this type of boiler 30. (and assuming we are dealin with one having three steam-andwater ruins) the fire gases flow from front to rear, making four passes after leaving the lire boX, these passes dependingon the disposition of the baffles in As a rule these baffles are disposed on the rear tubes of the first and second banks, reaching in the first instarrce from the mud drum t a point above the center of the first or front bank, and in 4o the second `instance from the center steamand-water drum to a suitable point above the mud drum but very nearly to the bottom of said second or middle bank. A defiecting shelf is placed near the top of the front baf- 415 lie, said shelf projecting rearwardly and substantially at right angles to the front baffle and terminating a suitable distance from the secondvor middle bank of tubes. A second shelf is placed near the top of the rear or third bank of tubes and deflects thegases in theirpassage upward through said bank, toward the tubesthus preyenting by-,passing between the tubes and the rear wall of the boiler setting. A re brick baffle directly over the water-circulating tubes between the Specification of Letters Patent. Pgbtntgdl Sept, 3:99 i919), application inea November 1s, 1917. serial No. 202,341.24.

front and middle steam-and-water drums prevents the gases passing above these tubes. The foregoing represents the general arrangement of a Stirling boiler; and since a single mud drum is connected with a series of three steam-and-water drums, the several banks of water-tubes necessarily must radirelative to the several banks of water tubes involved in the construction of a boiler of vthis type, that not only will the soot and other accumlations be effectively dislodged from the heating surfaces to which such material may adhere, but the same shall be carried toward the gas outlet flue of the furnace without in any wise disturbing the general line of draft defined by the passes followed by the fire gases. The advantages of the in- 'vention will be apparent from a detailed description thereof in connection with the-accompanying drawings, in which* Figure l 'represents a eide elevation of a Stirling boiler setting, l banks of circulating water tubes and the baf showing the several" ate or pitch from said mud-drum at different fles in dotted outline; and showing my im- Y.

proved soot blower in side elevation applied to .the boiler; Fig. 2 is an enlarged vertical cross-section through the boiler setting on` the line 2 2 of iFig. 1- showing in front ele. Vation the so-called second blower unit, the same being broken at the middle; Fig. 3 is a middle vertical longitudinal section through the blowerl unit shown in Fig. 2; Fig. 4 is a vertical cross-section on 'the line 4--4 of Fig. 3; Fig. 5 is a vertical cross-section on the line 5 5 of Fig. 3; Fig. 6 is a vertical crosssection on the line 6 6 of Fig. 3; Fig. 7 is v an inner end view of the blower unit shown I tion on the line 11--11 ofFig.' 1 showin the rotatable jetpipe at the center tof-the middlebank of tubes ;,Fig. 12 is an inner'end elevation of .Figi '11,'the baiiie being in section;

fFig. 13isa front end View of the rotary; jet pipesho'wnin Figs. 11 and` 12.- or a View looking through the Second bank of tubes toward ythe middle baiiie; Fig. 14 is an en-.

larged middle horizontal section of the gear case in which is housed the gear joint by which thejetlpi-pe of 'the third-blower unit i .is actuated; Fig. is an enlarged Ihorizontal section on the line 15-15 f Fig.v 1; and

Fig. 16 is a vertical longitudinal sectional detail on the line 16-16 of Fig. 15. i

Referring to the drawings, F represents the boiler setting, B the fire box, l, 2, 3, the

' front, middle, and rear shells or steam-andwater drums respectively, 4, the mud drum, 5 the front bank ofcirculating water-tubes connecting the shell 1 with the mud-drum, 6 the middle bankof water-tubes, 7 the rear bank of water-tubes, 8 the steam tubes concent to the upper end of the baille, the mid-4 necting the front and middle shells, 9 the steam tubes connecting the middle and rear shells, 10 the water circulating tubes between the shells 1 and, 2, and 11 the tiling or baiiie directly over the tubes 10. 'The front baiile 12earried bythe rear members of the front bank of tubes 5 is provided with a shelf 13 at a point below but adjadle baiile 14 disposed on the rear of the A,middle bank of tubes 6 reaching from theA shell 2 to a point vnear the bottom of said bank and above the mudfdrum, and the baiile 15 at the rear of the rear bank of tubes 7 closing the opening between said bank and the rear wall of the boiler setting, the upper end of said baille terminating a suitable distance below the shell 3. 4The b'aile- 15,is in -the form of an angle bar, the

' horizontal -leg thereof engaging the rear.

wall of the boiler setting'and preventing bypassing of the gases between said wall and the rear bank of tubes 7. The 'foregoing features are well understood inthe art and vform no part of the present invention. The

arrows in Fig. 1 represent the general course of the furnace gases and `combustion products, the same traveling from front'to rear and making practically four passes, to wit:

(1) upwardly from the fire-box B through .the bank of tubes 5 over the front baiiie 12 and around the shelfl 13; (2) downwardly through the middle bank of tubes 6 'below the lower edge of the middle baille 14; (3) upwardly through the rear bank of tubes 7 over the top ofthe rear baiiies 15; and (4) downwardly and horizontally through the exit'- or outlet opening E, the gases of course always traveling rearwardly and playing over the heating surfaces ofthe shells 1,A 2, 3, and the circulating tubes 10, and T, the latterl designating the severa-l ing usually dry.

tubesincludedin tliei'espective banks 5, 6, i

and 7. "To properly blow7 or clean afboiler of this character, due regardl must be had not l only for the'disposition of the several banks oftubes T,vbu'tfor-the course or general di rection of theire gases or draft, the blower nozzles or jets being. so arranged that the general line 4of draft shall not be disturbed;

otherwise there would vbe danger of banking or backing the fire. This point will be clearly brought out when we come to consider the disposition of the several blower units as here constructed. P, represents the steaml or cleaning-fluid supply-pipe, the

same being preferably coupled to the middle orhighest shell 2, the steam therein be- Any other source vof steam supply'can however be availed of if necessary or convenient. Disposed on top of,

and embedded in the bridge-'wall 16 ofthe boiler setting, at the base and in front of,

the iirst bank 5 of circulating water tubes,' and in proximity to the mud-drum 4, is a stationary jet-pipe 17, the same extending across the boiler and substantially the full length of the bridge-wall'. Radiating from peripheral openings of said pipe are nozzles 18 preferably disposed` in transverse clusters of three spaced appropriate distances apart along the length ofthe pipe, the radial disposition of the nozzles of each cluster .permitting the jets' of steam (or other cleaning fluid) i discharged therefrom to be rojected radially outward from the axis of the jet-pipe, the `clusters being disposed in vertical planes at points opposite the spaces between the tubes T of the first .bank 5 of circulating water'tubes (Fig. 9),

the discharge from any cluster of nozzles assuming more or less the form of a flaring sheet of steam which readily penetrates the spaces between the tubes (5), the general di i the `side wall of the Iboiler setting and closed by a plate 20. To install the pipe' 17 a suitable depression or basin is first formed in the bridge wall, said basin opening at the' outer end opposite the bushing 20. This permits the pipe to be inserted into position, after which a filler21of refractory material or lire clay is packed around the pipe and around lthe nozzles 18, the discharge ends of the nozzles being flush with thecrown or archedy portion ofthe vller (Fig. 10). The jet pipe 17 pipe 17 traverses a bushing 2O embedded in Vnio 30 the ring 29 is spaced from the peripheral Larmes j with its nozzles 18 .constitutes the first blower unit of the series, and is fixed, no movement being .imparted thereto during the blowing operation. v j

Leading `from the frontv terminal of the lower horizontal branch orY leg of the supply pipe P is a riser or header 22 whose upper end terminates at Va point just below the baffle 11 between rthe shells 1 and 2. The said riser is provided with any conventional form of hollow swivel joint 23 to the rotary member of which (well understood in the art)v is coupled the outer end of the jet-pipe 24 of the second blower unit, said pipe being disposed rearward of the bank of tubes 5 and p-arallel to Iand rearward of the shell 1 and parallel to the pipe 17. rlhe outer end of Ithe pipe 24 passes through a bushing 25 embedded in the side wall of the boilersetting and is partly supported in avbearing plate 26 closing the outer end of the bushing. The inne; end of theijet-pipe is supported by a bracket 27 Vclamp-ed to one of the water tubes 10 (Fig. 2) the semi-cylindrical upper terminal of said bracket which forms the immediate seat or bearing for the pipe being received by the annular recess h formed between the flanges 28, 28, of 4a ring 29 set-screwed to the pipe at the proper point to engage the bracket. The inner wall-oi:l

surface of the jet-pipe 24 by means of inwardly projecting bosses or lugs t formed on the ring, said lugs engaging the pipe and thereby leaving or forming circulating air `spaces -a between the lugs as best seen in Fig. 6. a fre-clay casing or sleeve 30 forming' an air jacket, vand preferably built up of a series of sections making rabbet joints with one another, each section in the region of the .joint between the sections being provided with spacing lugs or bosses t leaving cir@ culating air spaces a (Fig. 5), said spaces a', and the spaces a previously mentioned being -in free communication. with and forming part of the circulating air space s between the. casing 30 and the pipe 24. The terminal sectionsA of the casing or jacket 3() are supported by thev cap 31 and screw-cap 32 respectively, the former being adjustable and adapted to be setscrewed to the jet-pipe, and the latter screwed to the inner end of the pipe, this arrangement serving to force the several sections of the jacket into rm engagement with one another as well. as to clamp to the4 ring 29 the sections disposed on each side thereof. Preferablyand as shown in`Fig. 3, 4the terminal jacket section engaging the cap 31 has a reduced end which is received by an annular recess or groove in the cap whereby the said section is shouldered against the cap. On the other hand, the jacket section engaging the screw-cap 32 The jet-pipe 24 is protected by vthe bearing plate 26 isa bent vent-pipe 33 the outer end of which is open to the outer .air'thr'ough the peripheral wall of the jetpipe at a point beyond the air jacket, the inner end of the vent-pipe terminating behind the cap 31 and Ydischarging through the peripheral wall of the jet-pipe into the circulating air space s between the jacket 30 and j et-pipe, the inner terminal ofthe jacket being provided witha series of c ircularly disposed peripheral vent openings or ports 34 discharging into the combustion chamber of the boiler. rlhe jet-pipe 24fis equipped with a longitudinalrow of peripheral jet nozzles 35 which extend across the air space s and penetrate and discharge through the walls of the jacket 30, the said )nozzles serving to assist in securing the jacket to the jet-pipe, the two rotating as a unit when rotation is imparted to the jet-pipe. tion may be im arted to the jetepipe 24 in any suitable I nec anical manner, the method employed in the present illustration consisting of a chain sheaVe-wheel 36 coupled to the rotary member or element or" the swivel joint.23, said member being coupled as previously stated to the jet-pipe. By imparting rotation to the sheave-wheel it follows that rotation will necessarily be imparted to the pipe 24 and jacket 30,- the two rotating as a unit about a common axis. llhe sheavewheel 36 is operated by an endless chain37 hanging within easy reach of the engineer or operator. Like the branch 19, the riser i 22 is provided with a hand valve'V where necessary, a drain valve or cock 38 beingI positioned at the lower end of the bottom horizontal leg of the pipe P for carrying oliy any water of condensation as well understood in the art. rlhe jet nozzles 35 are so disposed or spaced along the pipe24 as to sweep in vertical longitudinal planes between the tubes 10, whereby upon rotation of the pipe the cleanin jets will play in the spaces between said tu es, and in the spaces between the tubes in the upper region of the .first bank of tubes 5. The draft of the boiler' furnace will naturally and at all times induce a flow of Acool atmospheric air through the vent pipe 33, and air space s and into the combustion chamber through the vent nozzles 34, so that overheating or f burning out of the pipe 24 is prevented. The

Rota-- spaces will not cause any material drop in the temperature of the steam blowing through the ljet-pipe to-.eause condensation,

l -soy that no air'can escape ,from-the jacket it being understoodthat in bio'wingor clean- -ing a boiler with steam', the Asteam shouldbe 1 as dry as possible to prevent baking. or

caking of the-sootand'ashesfo.' the .boiler tubes. The-.openin gs in the peripheral wall of thesleeve 30 throughr whichzthe nozzles '35' are 'inserted are conical or outwardly'flaring, andv when' the partslare assembled Nthe spaces around the nozzles are 'sealed witha' filler 39 of refractory material or fire clay,

v untilthevents-34are reached. In the. type of boiler hereshown and to whiclithepreslvent"cleaning.'system is applied,l the most ini tense heatl is in 'the region of the first and i For this reason the' rstvunitfis embedded ina layer of refrac` I tory material-.in the bridge-wall, and the secondj Vblower units.

jet-pipe of the' second unit is .protected by an air jacket 'formed by a sleeve or 'casing fof refractory material 7surrounding the pipe `'and leaving an air circulating space s as a1- readyfdescribed..

"1 )The third blowerunit inthe." present installation operates between the first and sec- 0nd' baiiies, and 'is practically confined in 'its operation to" the Scond bank 'of tubes 6. This unit is substantially. ts-follows: Leading from the b cfittom` horizontal leg of the" supply pipe P is'a'iiser or`header 40 pro- 'vided with a hand-valve V', and terminating at the top in a horizontal pipe or leg 40". The pipe 40 iscoupled-to a T41 at the outer'end-of a vstationary, 'steam conductingJ or supply-'pipe 42 disposed "rearward of the baiiie 14 and -ata suitable distance therefrom,

the inner end .of the pipe vterminating at substantially?ther-middle of the boiler. In other wordsthe pipe 42 terminates at a f.

point opposite they middle- (horizontally) of themiddle bank of tubes 6, and `substantially midway between the shell 2 andthe muddruln 4. The outer end-of the pipe 42 passes 1 through a bushing '43 in the side' Wall of the boiler setting, the inner end of the pipe -being connected as shown, to the gear case'4'1' of' an angle gear .joint (presently vto be described) said' case being preferably made in two sections bolted together as shown (Fig.

14) and supported by a bracket 45 projecting through the vertical baile 14, the bracketbeing itself clamped to a tube T adjacent the baffle. Traversing the pipe` 42 and projeeting through* a stufiing-box 46:01; the T 4 1- is a .gear-shaft 47, the outer end of which, isprovided with a chain sheave-wheel 48 actuated by a chain 49 within easy reach of the engineer or operator, Thev inner end of the gear-shaft .is supported by bearings' 50`in the gear case (Fig. 14) and terminates ina bevel pinion v51 .which meshes with a bevel gear ring 52 set to rotate in a plane at fright' anglesv tothe plane of rotation of the pinion, whereby there is formedv within the gear case44 (housing said pinion and gear rotation `is transmittedto the hollow shaft .1ing) a gear-joint. capable of transmittingv f'rotation'from the gearlshafjt147 to anyfother shaft or equivalent member whose axis offro'- tation isfdisposedat right anglesfto that of the gear-shaft. In the Apresent instance this "53 .-to, 1whieh thel gearxlinglis secured.` The. I

inner end of the hollow shaft 53 terminates ina spindle or bearing 54 supported by one of. theseetions of .theg'ear case, the said`f shaft beingprovided with peripherall cir 1 culating openings 0 adjacent the bearing 54.

The outer projecting portion of the hollow shaft 53 'terminates ina flange 55 to which is bolted' the'ring 56 intowhich the adjacent end of the rotary jet-pipe 57 is screwed, an.

openingObeing'formed in the'baflie 14 to accommodate said pipe. The opposite end of the pipe 57 `-`is closed hy a cap 58 which-is providedwith a spindle 59, Said spindle being supported lby a strap 60 clampedabout one ofthe tubes T Yforming the front row of the middle or second lbank of tubes 6. The hollow shaft 'operates in a stuling-box 6l; and thegear-shaft47 is preferably connected to thebevel pinion l'through a leXible joint 62 as shown (Fig.` 14). The jet- 'I i pipe 57 operates at the centerof the middle bank of tubes, andl has rotation imparted thereto'by thehollow-shaft 53 to which it bank of tubes. The said jet-pipe 57 is proioo vided with peripheral radially discharging nozzles 63' on the. order of the nozzles 18 35, said nozzles 63 being disposed in the transverse spaces between the tubes (or spaces between the transverse rowsI of tubes) of the second 'or middle bank of water tubes, whereby upon rotation"Y being imparted to the jet-pipe, the nozzles will projectthe cleaning fluid`(steam) into the spaces beallel to said spaces and'parallel to the pitch 'of the tubes. 'It may be stated in passing that the steam inds it way to the jet-pipe 57 through the hollow shaft 53, into which ypassesfrom' theJ riser 40, through the sta-4 tionary supply pipe 42, the latter discharging into the gear-case 44 in which the steam freely circulates around the gear-shaft 47', flexible joint 62 `and bevel pinion 51,` flowing thence through the openings o of the' hollow shaft-53A and into the jet-pipe 57 (Fig. 14.) Rotation'imparted to the gearshaft 47 from the Wheel 48 is necessarily imparted to the jet-pipe 57 in consequence l tween the tubes in planes4 substantially parparallel vertical planes into and throu h they minces 'whereof the nozzles 63 will sweep and discharge the steam in the paths previously described.

The fourth and last blower unit of the series is substantially the same as unit number two, with the exception of the air jacket, it being understood that units numbers three and four require no air jackets, being located in regions where thetemperature of the gases is insuificient to exert any material destructive effects on the jet-pipes. The fourth unit may be described as follows: vLeading fromy the bottom horizontal leg of the supply pipe P is a riser or header` 64 provided `with a hand-valve V, said riser terminating atthe top in a hollow swivel joint 65 to the rotary member of which is secured at one end .the chain vsheave-wheel 66 provided with an operating chain 67, the other end of the rotary member having coupled thereto ythe o uter terminal `of the transversely disposed jet-pipe68 whose inner end is closed by'a'fcap 6,9. The outer end of the jet-pipe passes through a bushing 70 in the side wall of the boiler setting, said bushing being closed along the outer face of the wall by a plate or ring 71 forming a bearing for the jet-pipe. The pipe issupported at its inner end by a bracket 72 clamped to one of the tubesT of thethird bank of tubes 7, the said jet-pipe runningparallel to said bank across the boiler and rearward of and adjacent` to the lower end of said bank and at a suitable distance rearward ofthe mud-` drum 4. The jet/.pipe`68 is likewise parallel to the pipes 17 and 24 and perpendicular to the jet-pipe 57 of the third unit. The jetpipe 68 is provided with a rowof nozzles 73 on the .order of` the nozzles ofthe jetpipes ofthe previous units described, said vnozzles 73 being spaced so as to project the cleaning fluid into the spaces lbetween the tubes T of the thirdbank of tubes 7,. the cleaning iluid (steam) reaching said nozzles by way of the riser 64, the hollow swivel joint 65 *(whichmay be-of any .approvedV` cumulations deposited thereon by the gasesr their travel from the fire boX rearward through the combustion 'chamber of the boiler toward the eXitfiue E. In the pres-` ent embodiment of my invention the j et-pipe 17 of the first blower unit is stationary, the ports or nozzles 18 being so directed as to project the steam. jets radially upward in spaces between the first bank oftu es 5,

I' these planes of projection as obvious from- Figs. 1, 9, and lO, being longitudinally of j (or other fluid) escap-.'

.iii

uw boiler or parallel to the Side Wang of the setting between which the drums v1, 2,

8, and 4 are mounted. rIhe jets of steam thus projected take th general upward direction of the fire gases through the rst gas pass, the tubes being cleaned or blown well up toward and perhaps above the upper end of the first baiie 12. The jet-pipes24, 57, and 68 entering into the construction of the second, third,.and fourth blower units respectively, are all freelfy7 rotatable about their the. upper portions of the tubes of the first l bank of tubes 5, or those portions/above the upperl end of the baffle 12. By rotating said pipe 24 in proper direction, we maywcause the steam jets to be projected obliqtiely downward -and rearward into and through the spaces between the upper portions of the tubes `6 of the middle bank as vclearly ap parent from Fig. 1. To clean the tubes' 10j a'nd the. upper portions of the tubes of the first and second banks as described, we need i not rotate the jet-pipe 24 full three hundred and sixty degrees. A half revolution will sufice to enable the steam jets to reach. the portions of the tubes designed to be".4 cleaned by'this unit. vLike in the the planes of projection of the steam@ from the second unit are longitudinal ofxt I boiler (the `term longitudinal herein beingY used -to designate the general direction from the lire box B toward the gas exit E) and at right' angles to the general planes of inclination or pitch'of the tubes. rIhe jets die rected against the upper portions of the first ice -rst i its bank of tubes 5 while in a measure acting against the upward draft in the first gas pass they at the same time intensify the `downward draftA in the second gas pass, so

that the general direction of the draft isnot' interfered with. 0f course,l in blowing down toward the upper portions of the middle bank oftubes 6 the blowing actionis wholly favor or in the general downward directlon,

4tensionjof said jet-pipe. In practice the ipe 57 is rotated a full three hundred and sixty iis . degrees, the steam -jets issuing from the nozzles 63 thereof being thereby projected into the spaces between the tubes ofthe second bank in transverse planes substantially parallel to the dip or'pitch of the tubes, said planes' of projections being at right angles l to the vertical longitudinal planes of projecthe drawings.

tion of the -jets of steam from the jetpipes 17 and 24: of the first and .second blower Aunits'respectively This follows from the fact that the sweep of the nozzles 63 of the third blower unit is transverse to the sweep v of the nozzles of the second blower unit,

and transverse to the planes of the steam sheets'formed by the successive clusters of `radial nozzles 18 disposed transversely across the periphery of the jet-pipe 17 of the first blower unit. In practice the pipe 57 -may be rotated back and forth until the steam jets have cleaned the tubes of all accumulations of soot, ashes and other deosits. l/Vhen the nozzles 63 are pointing downward the downdraft in thesecond gas pass is materially intensified as obvious from When these nozzles point upward the general line of draft is not disturbed because of the fact that in blowing upward along the tubes of the second bank the vacuum produced -below the jet-pipe 57 draws in a measure the gases of the natural draft downward in the general direction 'of the second pass) between the baille 12 and Ythe front transverse row of tubes of the middle bank of tubes 6, 'so that here again the natural draft instead of being interfered with is in fact not materially disturbed if at all. A complete rotation of the pipe 57 will causev the jets from the nozzles 63 to reach every portion of the surface of the tubes of the middle bank and clean them thoroughly. The upper portions of these same tubes may likewise be cleaned by the jets from the pipe 24 of the second unit as already described; and since the jets from the pipe of the second unit play against the tunes (of the middle bank) at right angles to the planes of projection of the jets from the pipe 57, it follows that the jets will reach all around the tubes'and a most thorough and complete cleaning of the upper half of the middle bank of tubes may thus be efected. In the same way and for a like reason an equally thorough cleaning of the lower half of this bank may beeiected, it being remembered that the planes of projection of the jets rfrom the pipe 68 of the i' fourth or last unit are likewise at right angles to the planes of projection of the jets -from the pipe57. In other words by imy parting the required .degree of rotationto the jet-pipe 68 the nozzle 73 thereof can be` made to project the jets issuing from them (into the spaces between the lower portions of the tubes of the third bank 7) well into the spaces between the lower half of the tubes of the middle bank. It is of course n ot necessary under ordinary service conditions to make -use of eitherv the second or fourth blower unit to clean the middle bank` of tubes, the jet pipe 57 of the third blower unit being su cient to'take care of this bank; but there may be circumstances where the engineer might find it vdesirable to. supplement the action ofthe pipe 5 7 by the pipes 24 and 68 of the second and fourth units respectively, as above explained. The fourth unit is in the majority of cases restricted in its operation to the third bank of tubes7. It will be seen (Figs. l, 15, 16) that a rotation of the jet pipe of this unit through a proper arc will cause the'nozzles 7 3 thereof to project the cleaning fluid-into and through the spaces between the tubes of this bank, the paths of projection being in longitudinalvertical` planesthe same as the jets issuing from units numbers one and two.

The angle or arc through which the jet pipe -4 of any rotatable u1 it is rotated in the blowing operation is a matterof judgment on the part vof the operator,-but of course the rotation should `always be sulicient to cause the cleaning fluid to reach as much of the exposed heating surfaces of the bank of tubes being cleaned, as is possible with the particular unit -under manipulation. It will be seen that banks 5 and 7 are cleaned by jets proj ectd in vertical longitudinal planes from blower units numbersvone, two and four; and the middle bank' 6 may be cleaned either wholly by unit number 3 (pipe 57) which projects thecleaningg; fluid iii transverse planes parallel to the pitch of thev tubes of said bank, or the action of said third'unit may be supplemented by the jetpipes 24 and 68 of units two and four wherein the paths of projection of the fluid are in vertical longitudinal planes, or transnumber one and end with unit number four.v

The state of soot accumulation may b e such that it may not be necessary to operate all the unitsV every time the boiler isblown or cleaned. yIt may be'that the accumulation -on a given bank of' tubes may be negligible whereas onr anotherbank it may be considerable. Of course to clean the boiler thoroughly and completely all the units should be blown, the particular sequence fol-A 2l. The air escaping from the air jacket of the second unit into the combustion chamber does not take part in the cleaning operation, the venting of the jacket being of course necessary to keep the air circulating around the jet-pipe 24. It is to be noted that the details of the construction here shown may be altered in manyl particulars without departing from the nature or spirit of the invention. Features shown but not alluded to are well understood in the artand need not be described in the present connection. It is further to be understood that lthe applica.-

' tion of my invention or parts' thereof is not to be restricted to cleaning Stirling boilers, but with4 certain changes of detail falling within the purview of the skilled mechanic the invention may be applied to other types of water tube boilers, as for example the Babcock da W'ilcox, commonly known as the B. @o W. water tube boiler.

' Having described my invention what I claim is:

l. In a boiler of the'charaGter described, a jet-pipe provided with peripheral openings, a casing or sleeve surrounding the same` and spaced therefrom and forming an airjacket around the pipe, the casing being provided with vent openings, and a ventpipe disposed in the jet-pipe having an intake terminal open to the atmosphere through the wall of the jet-pipe at a point beyond or Y outside the casing, and having adischarge terminal opening through the wall of the jet-pipe into the air-jacket formed by the casing.

2. A blower unit for boilers comprising a rotary jet-pipe provided with nozzles projecting beyond the peripheral surface of the pipe, and having an intake 'end for the clean- '.in fluid, an adjustable ring on the pipe a apted to be secured to the pipe at any predetermined point, terminal caps on said pipe, a sleeve or casing comprising a plurality of sections spaced from the pipe and` forming an air-jacket for Athe same, the casing sections being supported' between the intermediate adjustable ring and the termlnal caps aforesaid, said sections and the adjustable ring beingl provided with bosses or lugs on their inner surfaces for engagingthe periphery of the pipe, said bossesA being spaced circularly apart to leave spaces -establishing intereommuni'cation with the air-jacket spaces on either side thereof, the intermediate ring being providedwith a peripheral depression to receive ya suitable bearing, suitable vent openings being formed in the jacket wall in proximity to the inner terminal of the blower unit, a vent-pipe disposed at the outer terminal of the unit within the jet pipe, the intake end of said vent-pipe opening'to the atmosphere through the wall of the etpipe at a point outside the air jacket, and having a discharge end open to the air acket through the wall of the jetpipe at a point rearward ofthe front acketsupporting cap, the blower nozzles leading from the walls of the jet-pipe across the airjacket and discharging through the walls ,of the easing aforesaid, saidcasingbeing composed of refractory material.

In testimony whereof I ai'liX my signature,

in presence of two witnesses.

y LEO JNO. BAYER. lVitnesses EMrn STAREK,

Jos. A. MICHEL. 

